There are at least 6 common classifications of bearings, each of which works differently:
1. Sliding bearings, consisting of a shaft that rotates in a hole. There are several specific styles: bushings, journal bearings, sleeve bearings, Rifle bearings, composite bearings;
2. Rolling element bearings, in which the rolling elements are placed between the rotating race and the fixed race to prevent sliding friction. There are two main types:
3. Ball bearings, in which the rolling elements are spherical balls;
4. Roller bearings, in which the rolling elements are cylindrical, conical and spherical rollers;
5. Gem bearing, a sliding bearing in which one bearing surface is made of super hard glass gem material, such as sapphire, to reduce friction and wear;
6. Fluid bearing, a non-contact bearing in which the load is supported by gas or liquid (ie, air bearing);
7. Magnetic bearings, where the load is supported by the magnetic field;
8. Bending bearings, where motion is supported by a bending load element.